Answer

$(5n+2)(4n-3)$

Work Step by Step

Using factoring by grouping, the factored form of the given expression, $
20n^2+8n-15n-6
,$ is
\begin{array}{l}\require{cancel}
(20n^2+8n)-(15n+6)
\\\\=
4n(5n+2)-3(5n+2)
\\\\=
(5n+2)(4n-3)
.\end{array}